Through wafer vias are used to form electrical contacts from the front side to the backside of semiconductor substrates. Through wafer vias may be insulated or un-insulated from the substrate. Un-insulated vias are used primarily for low-impedance ground contacts in radio frequency (RF) integrated circuits. For certain RF applications semiconductor substrates with very low substrate doping levels are used. The use of conventional un-insulated through wafer vias and very low semiconductor substrate doping levels can lead to undesired current flows between device structures fabricated in the semiconductor substrate and the through wafer vias. Accordingly, there exists a need in the art to eliminate the deficiencies and limitations described hereinabove.